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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
//
// Description:
// Map of annotation instances handed out by a particular store.
// Used to guarantee only one instance of an annotation is ever
// produced. Also register for notifications on the instances
// and passes change notifications on to the store.
//
// Spec: CAF Storage Spec.doc
//
using System.Windows.Annotations;
namespace MS.Internal.Annotations.Storage
{
/// <summary>
/// A map the store uses to maintain having one instance
/// of the object model
/// </summary>
internal class StoreAnnotationsMap
{
//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
#region Constructors
/// <summary>
/// Constructor for StoreAnnotationsMap
/// It takes instances of the AnnotationAuthorChangedEventHandler, AnnotationResourceChangedEventHandler, AnnotationResourceChangedEventHandler delegates
/// </summary>
/// <param name="authorChanged">delegate used to register for AuthorChanged events on all annotations</param>
/// <param name="anchorChanged">delegate used to register for AnchorChanged events on all annotations</param>
/// <param name="cargoChanged">delegate used to register for CargoChanged events on all annotations</param>
internal StoreAnnotationsMap(AnnotationAuthorChangedEventHandler authorChanged, AnnotationResourceChangedEventHandler anchorChanged, AnnotationResourceChangedEventHandler cargoChanged)
{
Debug.Assert(authorChanged != null && anchorChanged != null && cargoChanged != null,
"Author and Anchor and Cargo must not be null");
_authorChanged = authorChanged;
_anchorChanged = anchorChanged;
_cargoChanged = cargoChanged;
}
#endregion Constructors
//------------------------------------------------------
//
// Public Methods
//
//------------------------------------------------------
#region Public Methods
/// <summary>
/// Add an annotation to the map
/// throws an exception if the annotation already exists
/// </summary>
/// <param name="annotation">instance of annotation to add to the map</param>
/// <param name="dirty">the initial dirty flag of the annotation in the map</param>
public void AddAnnotation(Annotation annotation, bool dirty)
{
Debug.Assert(FindAnnotation(annotation.Id) == null, "annotation not found");
annotation.AuthorChanged += OnAuthorChanged;
annotation.AnchorChanged += OnAnchorChanged;
annotation.CargoChanged += OnCargoChanged;
_currentAnnotations.Add(annotation.Id, new CachedAnnotation(annotation, dirty));
}
/// <summary>
/// remove an annotation from the map if it exists
/// otherwise return
/// </summary>
/// <param name="id">id of the annotation to remove</param>
public void RemoveAnnotation(Guid id)
{
CachedAnnotation existingCachedAnnot = null;
if (_currentAnnotations.TryGetValue(id, out existingCachedAnnot))
{
existingCachedAnnot.Annotation.AuthorChanged -= OnAuthorChanged;
existingCachedAnnot.Annotation.AnchorChanged -= OnAnchorChanged;
existingCachedAnnot.Annotation.CargoChanged -= OnCargoChanged;
_currentAnnotations.Remove(id);
}
}
/// <summary>
/// Queries the store map for annotations that have an anchor
/// that contains a locator that begins with the locator parts
/// in anchorLocator.
/// </summary>
/// <param name="anchorLocator">the locator we are looking for</param>
/// <returns>
/// A list of annotations that have locators in their anchors
/// starting with the same locator parts list as of the input locator
/// If no such annotations an empty list will be returned. The method
/// never returns null.
/// </returns>
public Dictionary<Guid, Annotation> FindAnnotations(ContentLocator anchorLocator)
{
ArgumentNullException.ThrowIfNull(anchorLocator);
Dictionary<Guid, Annotation> annotations = new Dictionary<Guid, Annotation>();
// In the future, this probably has to be done in a way more effecient than linear search
// the plan of record is to start with this and improve later
// the map is already solving a perf bottleneck for tablet
Dictionary<Guid, CachedAnnotation>.ValueCollection.Enumerator annotationsEnumerator = _currentAnnotations.Values.GetEnumerator();
while (annotationsEnumerator.MoveNext())
{
Annotation annotation = annotationsEnumerator.Current.Annotation;
bool matchesQuery = false;
foreach (AnnotationResource resource in annotation.Anchors)
{
foreach (ContentLocatorBase locator in resource.ContentLocators)
{
ContentLocator ContentLocator = locator as ContentLocator;
if (ContentLocator != null)
{
if (ContentLocator.StartsWith(anchorLocator))
{
matchesQuery = true;
}
}
else
{
ContentLocatorGroup ContentLocatorGroup = locator as ContentLocatorGroup;
if (ContentLocatorGroup != null)
{
foreach (ContentLocator list in ContentLocatorGroup.Locators)
{
if (list.StartsWith(anchorLocator))
{
matchesQuery = true;
break;
}
}
}
}
if (matchesQuery)
{
annotations.Add(annotation.Id, annotation);
break;
}
}
if (matchesQuery)
break;
}
}
return annotations;
}
/// <summary>
/// Returns a dictionary of all annotations in the map
/// </summary>
/// <returns>annotations list. Can return an empty list, but never null.</returns>
public Dictionary<Guid, Annotation> FindAnnotations()
{
Dictionary<Guid, Annotation> annotations = new Dictionary<Guid, Annotation>();
foreach (KeyValuePair<Guid, CachedAnnotation> annotKV in _currentAnnotations)
{
annotations.Add(annotKV.Key, annotKV.Value.Annotation);
}
return annotations;
}
/// <summary>
/// Find an annottaion that has a specific id in the map
/// returns null if not found
/// </summary>
/// <param name="id">id of the annotation to find</param>
public Annotation FindAnnotation(Guid id)
{
CachedAnnotation cachedAnnotation = null;
if (_currentAnnotations.TryGetValue(id, out cachedAnnotation))
{
return cachedAnnotation.Annotation;
}
return null;
}
/// <summary>
/// Returns a list of all dirty annotations in the map
/// </summary>
/// <returns>annotations list. Can return an empty list, but never null.</returns>
public List<Annotation> FindDirtyAnnotations()
{
List<Annotation> annotations = new List<Annotation>();
foreach (KeyValuePair<Guid, CachedAnnotation> annotKV in _currentAnnotations)
{
if (annotKV.Value.Dirty)
{
annotations.Add(annotKV.Value.Annotation);
}
}
return annotations;
}
/// <summary>
/// Sets all the dirty annotations in the map to clean
/// </summary>
public void ValidateDirtyAnnotations()
{
foreach (KeyValuePair<Guid, CachedAnnotation> annotKV in _currentAnnotations)
{
if (annotKV.Value.Dirty)
{
annotKV.Value.Dirty = false;
}
}
}
#endregion Public Methods
//------------------------------------------------------
//
// Private Methods
//
//------------------------------------------------------
#region Private Methods
/// <summary>
/// the event handler for AnchorChanged Annotation event
/// internally it calls the store AnnotationModified delegate
/// </summary>
/// <param name="sender">annotation that changed</param>
/// <param name="args">args describing the change</param>
private void OnAnchorChanged(object sender, AnnotationResourceChangedEventArgs args)
{
_currentAnnotations[args.Annotation.Id].Dirty = true;
_anchorChanged(sender, args);
}
/// <summary>
/// the event handler for CargoChanged Annotation event
/// internally it calls the store AnnotationModified delegate
/// </summary>
/// <param name="sender">annotation that changed</param>
/// <param name="args">args describing the change</param>
private void OnCargoChanged(object sender, AnnotationResourceChangedEventArgs args)
{
_currentAnnotations[args.Annotation.Id].Dirty = true;
_cargoChanged(sender, args);
}
/// <summary>
/// the event handler for AuthorChanged Annotation event
/// internally it calls the store AnnotationModified delegate
/// </summary>
/// <param name="sender">annotation that changed</param>
/// <param name="args">args describing the change</param>
private void OnAuthorChanged(object sender, AnnotationAuthorChangedEventArgs args)
{
_currentAnnotations[args.Annotation.Id].Dirty = true;
_authorChanged(sender, args);
}
#endregion Private Methods
//------------------------------------------------------
//
// Private Fields
//
//------------------------------------------------------
#region Private Fields
// a dictionary that holds an annotation id to an annotation instance
private Dictionary<Guid, CachedAnnotation> _currentAnnotations = new Dictionary<Guid, CachedAnnotation>();
// The delegates to be notified for Annotation changes
private AnnotationAuthorChangedEventHandler _authorChanged;
private AnnotationResourceChangedEventHandler _anchorChanged;
private AnnotationResourceChangedEventHandler _cargoChanged;
#endregion Private Fields
//------------------------------------------------------
//
// Private Classes
//
//------------------------------------------------------
#region Private Classes
/// <summary>
/// This class contains an annotation and a dirty flag
/// It is needed because when it is time to flush
/// the store - we should write only dirty annotations
/// </summary>
private class CachedAnnotation
{
/// <summary>
/// Construct a CachedAnnotation
/// </summary>
/// <param name="annotation">The annotation instance to be cached</param>
/// <param name="dirty">A flag to indicate if the annotation is dirty</param>
public CachedAnnotation(Annotation annotation, bool dirty)
{
Annotation = annotation;
Dirty = dirty;
}
/// <summary>
/// The cached Annotation instance
/// </summary>
/// <value></value>
public Annotation Annotation
{
get { return _annotation; }
set { _annotation = value; }
}
/// <summary>
/// A flag to indicate if the cached annotation is dirty or not
/// </summary>
/// <value></value>
public bool Dirty
{
get { return _dirty; }
set { _dirty = value; }
}
private Annotation _annotation;
private bool _dirty;
}
#endregion Private Classes
}
}
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